Copper-aluminium alloy as sealing casing in a pressure vessel (EN 13445)

[Mihe]

Hi, I am designing a hydraulic cylinder to comply with European pressure vessel code EN 13445.
The sealing casing will if possible be of copper-aluminium alloy EN1982 CC333G. The seal and casing is subjected to the internal pressure.

I can not find CC333G or any other copper-aluminium alloy in EN 13445. There is another standard EN 1653 "Copper and copper alloys -Plate, sheet and circles for boilers, pressure vessels and hot water storage units" but that standard is not referenced from EN 13445. It also does not include CC333G.

The design pressure is 200bar. I understand that I will have to verify the strength of the part but before I get started I need to figure out if there is any chance that this can be inline with the 13445 code. I believe CC333G or similar copper-aluminium alloy are quite common as casing/house for seals and guides of rods in hydraulic cylinders. But I have not seen how reference to the material can be inline with EN 13445.

Question:
-Can it be possible to use CC333G in the hydraulic cylinder, even though there is no clear reference for this material in EN 13445? -How?
I appreciate any hint from you!
BR/Mihe

 

[XL83NL]

You may be right that specific material isnt listed/referenced in EN 13445, but have you checked EN 13445-8? See

https://www.unm.fr/en/homepage/activities/maintenance-agencies/en-13445?pag_id=120

It's called "Additional requirements for pressure vessels of aluminum and aluminum alloys".

That being said, you can use any material you like under EN 13445, provided it meets the requirements of the applicable parts. That would be part 2 (EN 13445-2) and perhaps part 8.
Under part 2, see chapter 4. Para 4.3.3 would allow the use of PMA's, a method we've used quite often.

You mention it's hydraulic cylinder. Does that fall under the scope of the PED 2014/68/EU? My first idea would be no.
Nevertheless, any pressure bearing device should be designed for sufficient strength.

Can you provide a bit more background to the design, like design temperature range?
Key to using materials that aren't 'listed' is to know the allowable stresses at temperature. If this device is solely intended for ambient conditions, and the materials mechanical properties don't vary with increasing temperature, that might make a few things easier.

Huub
- You never get what you expect, you only get what you inspect.

 

[Mihe]

Thank you for your inputs!
I will look through -8 and -2 as you indicate.

I think your idea is correct. I found this:

https://ec.europa.eu/docsroom/documents/41641.

Page 28 says "Excluded from PED" ... "fluid power actuators (e.g. motors, cylinders, …)"

BR/Mihe

 

[XL83NL]

Correct. Nevertheless, EN 13445 can be used for the design, but Im sure there are probably other/better standards, more geared towards such applications.

Huub
- You never get what you expect, you only get what you inspect.